A zinc-aluminum alloy block is a thin casting made by co-melting a certain amount of pure zinc with a certain amount of pure aluminum. In hot-dip galvanizing production, it is difficult to add pure aluminum directly to the molten zinc bath because the temperature of the molten zinc is only between 470 and 510°C, while the melting point of aluminum is 660°C. However, according to the binary equilibrium diagram of zinc and aluminum, when the composition is approximately 7% aluminum and 93% zinc, the eutectic temperature is only around 380°C. A zinc-aluminum alloy block prepared with this ratio can be easily dissolved in the molten zinc bath, making it much more convenient to add the required aluminum element to the molten zinc in this way.
In actual production, for the convenience of calculating the aluminum content in the molten zinc, zinc-aluminum alloy blocks are also made with a composition of 10% pure aluminum and 90% pure zinc.
